Just start took car out for a spin and notice it would not accelerate like it should
will not accelerate when step on gas on 2000 Jaguar Vanden Plas
It could be many things, unfortunately and without experiencing the problem first hand or being able to do some basic diagnostic tests its hard to say. It could be a failing fuel pump, a restricted catalytic converter, a failing transmission, basic tests need to be done to get to the root of the problem. Is the Check Engine Light on?
This could be a possibility, it could be a OXYGEN SENSOR, with regulates how much throttle that gets delivered to the motor through the computer system. So for example, u can be going 30 mph when u are really going 10 mph. Hope this helps.